Error HTTP Status 404 - The installation of Jira 5.x

2012-06-28 02:50:54,393 jira-monitoring-plugin ERROR [jira.plugins.monitor.MetricsCollectorTask] Error running taskjava.lang.IllegalStateException: ComponentAccessor has not been initialised. at com.atlassian.jira.component.ComponentAccessor.getWorker(ComponentAccessor.java:848) at com.atlassian.jira.component.ComponentAccessor.getComponent(ComponentAccessor.java:105) at com.atlassian.jira.instrumentation.Instrumentation.getTenantedInstance(Instrumentation.java:63) at com.atlassian.jira.instrumentation.Instrumentation.getInstrument(Instrumentation.java:73) at com.atlassian.jira.plugins.monitor.database.ConnectionPoolGraph.setDatasourceValues(ConnectionPoolGraph.java:42) at com.atlassian.jira.plugins.monitor.rrd4j.RrdUpdater.addSample(RrdUpdater.java:74) at com.atlassian.jira.plugins.monitor.MetricsCollectorTask.doRun(MetricsCollectorTask.java:41) at com.atlassian.jira.plugins.monitor.MetricsCollectorTask.run(MetricsCollectorTask.java:30) at java.util.TimerThread.mainLoop(Timer.java:512) at java.util.TimerThread.run(Timer.java:462)